The U.S. Department of Energy has released a GATEWAY report on the experiences of the City of Portland, OR, in converting its street lighting from high-pressure sodium to LED. Such large-scale conversions are rarely simple matters, and the Portland Bureau of Transportation was an early investigator of LED street lighting and one of the first public agencies to join DOE's Municipal Solid-State Street Lighting Consortium, so learning how the city addressed the challenges it encountered can be especially helpful to other cities that are implementing or considering their own lighting transitions.
Projected dollar savings from Portland's completed conversion exceed $2 million per year and are expected to repay the total $18.5 million investment in the upgraded system within about eight years. Beyond that point, continued savings will be used for system maintenance and put into a capital replacement fund for poles and circuits and the next round of luminaire replacements.
Although the process of upgrading Portland's streetlights to LED was more complicated and lengthy than the city originally envisioned, overall Portland and its residents are pleased with the results.
